The invention consists in providing a structure for matching or adapting the impedance of plane transmission lines that need to go through a substrate.
The device of the invention is applicable to all high frequency applications and in particular to microwaves and to microstrip technology.
When transmitting or receiving microwave signals, it is often necessary to go from a hollow waveguide to a plane transmission line, e.g. a microstrip. This is conventionally done either by means of a coaxial waveguide whose core is extended by an antenna in order to provide electrical coupling (coupling parallel to the TE.sub.10 electric field of a ractangular waveguide or the TE.sub.11 electric field of a circular waveguide) or else by means of a magnetic coupling loop placed on the narrow side of the waveguide. The other end of the core is perpendicular to a face of a substrate to which it is bonded. In devices where transmission and reception occur simultaneously, or where two orthogonally polarized waves co-exist, it may be necessary to pass through the substrate because of constraints on mechanical implementation.
The object of the invention is to make such an implementation possible.